1. Field of the Invention
He present invention relates to a LCD back light module structure, and more particularly, to a LCD back light module structure wherein a LED with high-crowned configuration is employed as a back light source to emit light uniformly on the LCD such that the LCD appears to be comfortably brilliant.
2. Description of the Prior Art
Generally, the white cold cathode fluorescent lamp (CCFL) is the most well-known LCD back light source. The LCD illuminated by a CCFL placed behind the LCD as a back light source. The capacity of CCFL and its driving circuit increases as the size of LCD increase. In order to strengthen the power output of the LCD back light, it is required to connect a plurality of CCFLS in series or parallel. But the things always have a limit, it is impossible to increase the output of a LCD back light source as large as possible only relying on CCFL. Moreover, the short life of CCFL affects the lifespan of the LCD. In addition to its high power consumption, the harmful ingredient of CCFL is a killer to environmental protection.
Accordingly, looking for a better LCD back light source is an urgent matter. A comparatively matured technical selection is a high intensity white LED. It has been a quite long experience using LED as a back light source for a small sized LCD screen such as in a cellular phone or on a PDA. Recently, following the improvement of the manufacturing technology, the brightness of the LED is remarkably upgraded, together with its compactness, light weight, rigidity, and long life, all these merits are summed up to cause the LED to become a first selection for the LCD back light source.
In a common practice for using the LED to form a LCD back light source, different numbers of LEDS are disposed at one or two sides of the LCD so as to display a picture on a LCD screen by the light outputted from the LEDS as long as the electric power is supplied. It should be understood that the light is not uniformly diffused from the LED, and instead, it is concentrated to intensively illuminate a limited spot leaving the comparative surrounding zones rather weakly illuminated. In order to overcome such a shortcoming, it is recommended to dispose the numbers of LEDS densely so as to connect side by side the illuminated zones of the proximate LEDS thereby attaining a uniform lighting effect. However, it is said that the optimistic gain is very little in comparison to a substantially large power consumption and material investment.
Aiming at the above depicted defects, the present invention is to propose a newly developed LCD back light module structure capable of palliating the inherent shortcomings of the conventional techniques.